1. Field of the Invention
The invention relates to method and device for training pelvic floor muscles in order to cure or prevent urinary or fecal incontinence.
More particularly, this invention pertains to novel method and device (perineometer) which can be used by medical professionals for diagnostic purposes and by woman or men at home or in non-medical environment for pelvic floor muscle exercise comprising contraction of the muscles, in order to maintain the muscle strength after childbirth so as to prevent urinary incontinence (prophylactic effect) or to provide increased muscle strength of a person who already suffers of urinary or focal incontinence in an effort to cure the incontinence (therapeutic effect).
2. Description of Related Art
The prevalence of urinary incontinence, especially among postmenopausal women, is estimated to be within 22-42% of the population. Up to 50 to 70% of the institutionalized female elderly are affected. The most common form is stress urinary incontinence. Incontinence may result from a sudden raise in bladder pressure that exceeds urethral resistance. This rise may occur under conditions such as coughing, sneezing, lifting, or some other form of activity.
Female continence is maintained through the integrated normal function of pelvic floor muscles, fascial structures, nerves, supporting ligaments, and the vagina. Different theories, e.g. Shafik's ‘common sphinkter’ concept, Delancey's ‘hammock’ hypothesis, and Petros'& Ulmsten's ‘integral theory’, are used to explain how this integrated system is mandatory for continence. The important role of normal functioning of pelvic floor tissues is common to these theories.
Continence might be maintained despite defective function in one or more of the structures involved in the continence mechanism through increased efficacy in the unaffected tissues. In some cases therefore, stress urinary incontinence might be the result of failed compensatory effects by the other tissues, e.g. reduced muscular force, reduced muscular endurance, or reduced active and passive tone of the pelvic floor muscles. Different studies have shown the importance of pelvic floor muscles in the maintenance of urinary continence. Appropriate pelvic muscle exercises have been found to strengthen the pelvic floor structures, which increases the capacity of the structures to maintain the continence mechanism, and thus reduces or eliminates urinary incontinence.
Among medical professionals, e.g. obstetricians, gynecologists, geriatricians, urotherapists, physiotherapists, and nurses, there is a general agreement that three different treatments exist for urinary incontinence. These include: pelvic exercises, medication, and surgery.
A H Kegel was among the first to document the positive effects of isometric exercises on the pelvic floor musculature. Kegel recommended the use of perineometers for biofeedback in pelvic muscle training. Simultaneous training with biofeedback has proven successful and has been corroborated by several investigators.
The Kegel perineometer suffered from several drawbacks. There was no provision in Kegel's vaginal probe for establishing a predetermined base-line pressure in the vaginal probe when the patient's vaginal muscles were relaxed. The manometer in the Kegel perineometer was difficult to read, both because the numbers and graduations were necessarily small to accommodate the full range of possible pressures on the dial face, and because small fluctuations in the strength of the patient's vaginal contractions could give rise to rapid and erratic movements of the manometer's indicating needle. The Kegel perineometer had no provisions for assisting the patient in timing or regulating the duration of her vaginal contractions, or for calculating the average strength thereof.
A variant of Kegel's device, disclosed in U.S. Pat. No. 2,507,858 issued May 16, 1950, comprises an inflatable member which can be inserted into vagina to indicate pneumatically the change in pressure on an associated dial gauge. U.S. Pat. No. 2,541,520 issued Feb. 13, 1951 to A. H. Kegel, illustrates a similar type of apparatus except that the applicator is inflatable via a pneumatic bulb.
Another variant of Kegel's perineometer was developed by Wilfred Lynch Associates of Racine, Wis. This device, called a pelvic floor exerciser, included a vaginal probe consisting of a sponge covered by a balloon. The probe is contracted prior to insertion by evacuating most of the air from the probe by means of a hand operated syringe. The patient then removes the syringe, caps off the opening of the probe, inserts the probe in her vagina, allows the probe to expand by uncapping the opening of the probe, and connects the opening of the probe to a flexible tube, which in turn is connected to a ball-in-tube meter apparently measuring the rate of change of the pressure in the probe.
When the pelvic floor exerciser is in use, the patient must keep one hand on the probe to retain it in her vaginal, and must hold the meter with her other hand so that the bell-in-tube portion is perpendicular to the ground. She then contracts her vaginal muscles and watches the ball as it rises and instantaneously falls again in response to the initial rate of change of her vaginal contraction. During the exercise the patient must perceive and record the maximum height reached by the ball in the tube. The difficulties with the Lynch exerciser are numerous and obvious. It is not an improvement of the Kegel's perineometer except for the fact that the vaginal probe is reduced in size prior to insertion.
Another variant of Kegel's perineometer has been developed recently by M. Dougherty at the College of Nursing of the University of Florida at Gainsville. This device involves an elaborate and expensive compressible intravaginal balloon device that is custom made to fit the interior of a particular patient's vagina. The device is then pneumatically connected to a pressure measuring device, the output of which is recorded on a strip chart. The Dougherty device has no apparent advantages over the original Kegel perineometer, except for the developer's contention that the device will not inadvertently slip out of the patients vagina. However, the device has many disadvantages, including that it is extremely expensive, requires a separate custom-fitted appliance for each patient, utilizes complex scientific instrumentation, and can only be used under the supervision of a skilled attendant.
Numerous types of perineometer-like devices are also described in the patent literature. For example, U.S. Pat. No. 3,598,106 issued Aug. 10, 1971 to E. Buning, describes a noninflatable liquid-filled pressure indicating vaginal exerciser utilizing a conventional fluid pressure measuring device. U.S. Pat. No. 3,640,284 issued Feb. 8, 1972 to P. A. Delangis, describes an apparatus which measures vaginal pressure by means of a cylindrical condom holder filled with water, and a manometer. U.S. Pat. No. 3,726,273 issued Apr. 10, 1973 to N. S. Cole, discloses a vaginal exercising device consisting of an inflatable bulb having only expansion capability. Vaginal pressure is indicated by a conventional pneumatic pressure indicator. U.S. Pat. No. 3,752,150 issued Aug. 14., 1973 to J. P. Harris, discloses a device for exercising vaginal muscles using a liquid-filled pressurized insert wherein the pressure caused by muscular contraction is indicated on a conventional liquid pressure measuring device. U.S. Pat. No. 3,926,178 issued Dec. 16, 1975 to A. N. Feldzarnen, includes a device for exercising sphincter muscles, including vaginal muscles, utilizing a noninflatable insertable probe having two helical tubes. Readout of the pressure sensed by the probe may be effected by means of a conventional Bourdon tube, a liquid level pressure sensor, tubes filled with colored liquid, or a conventional pressure gauge. U.S. Pat. No. 4,050,449 issued Sep. 27, 1977 to F. S. Castellana et al., describes an air inflatable balloon-like insertable member including a collar to hold the inflatable member in place. Pressure is measured by means of a conventional dial pressure gauge. U.S. Pat. No. 4,085,985 issued Sep. 20, 1977 to H. A. Sasse, describes an air or liquid filled elongated tube probe which is directly connected to a pressure indicating gauge. U.S. Pat. No. 4,167,338 issued Sep. 18, 1979 to H. Remih, discloses a circumferentially expandable insertable body and a conventional air actuated mechanical indicator. Alternatively, an electronic display for digitally providing a pressure indication may be utilized. U.S. Pat. No. 4,216,783 issued Aug. 12, 1980 to H. Kaiser et al., shows an insertable probe whereby vaginal pressure may be measured by a conventional air pressure gauge in connection with biofeedback to increase the degree and strength of control exercised over the vaginal muscles. U.S. Pat. No. 4,476,880 issued Oct. 16, 1984 to D. A. Giem et al., discloses an air pressure operated tubular membrane wherein air pressure is converted to an electrical signal by means of a sensor. By specifically disclosed electronic circuitry, a visual display of the vaginal pressure may be obtained. U.S. Pat. No. 4,653,514 issued Mar. 31, 1987 and U.S. Pat. No. 4,768,522 issued Sep. 6, 1988 to S. W. Shapiro, describes insertable members which are partially deflated by means of a vacuum before insertion into the vagina. U.S. Pat. No. 5,674,238 issued Oct. 7, 1997 to S. B. Sample et al., describes an insertable air filled probe whose interior pressure may be varied by vaginal contractions. The perineometer includes a control module which indicates alternating periods of exercise and rest so that the patient may contract the muscles according to a predetermined length of time separated by periods of rest. The controller also includes means for indicating the difference between the probe interior pressure and a predetermined pressure during the period of exercise, as well as means for indicating the difference between the average pressure of the probe interior during a preceding exercise period and a predetermined pressure during a period of rest. U.S. Pat. No. 5,733,230 issued Mar. 31, 1998 to D. J. Sawchuck et al., describes an insertable air filled probe connected to a pneumatic pressure generator supported by a microprocessor unit.
The above mentioned pressure sensors have some common major drawbacks: Balloons sense pressure changes without the possibility to sense from which direction the increase in pressure occurs. This means that an increase in intra-abdominal pressure or increased activity of other pelvic or hip muscles may give rise to an increased pressure reading without activity in the pelvic floor musculature. To reduce these errors, a simultaneous evaluation/examination of the movement of the pelvic floor by means of manual palpation or visual observation is necessary in order to get subjective information about the activity of the pelvic floor. In addition, since the changes in the diameter of the balloon cannot be measured during a test, nor the changes in physical characteristics, it is not possible reliably to calculate the forces developed in the pelvic floor by means of these techniques. Recent studies have shown that the force developed in the pelvic floor musculature increases as the length of these muscles increases. This implies that different sizes of the perineometers, e.g. different pressures within the balloons, is an important confounding variable which makes it difficult to compare the readings from time to time within each subject. In addition, a comparison between different groups of subjects seems impossible.
A very different approach to measuring the contractile strength of the vaginal musculature involves electro-myography. In this approach a set of electrodes is placed in physical contact with the interior walls of the patient's vagina. The electric potential differences among the probes are then measured by an electrometer, and from these measurements the degree of vaginal muscle contraction is inferred. Devices utilizing this approach are also called vaginal myographs.
Several vaginal myographs are marketed by Biotechnologies Inc. of Strafford, Pa. All myographs utilize a dumbbell-shaped solid vaginal probe which is made of hard dental acrylic, and which has three silver pads embedded around the contracted central portion of the probe. The probe is inserted into the patient's vagina, and is then connected by an electric cable to an assembly of amplifiers, integrators, computers, video displays, printers, recorders, telephone modems, quentized lighted bar displays, and other complex and expensive monitoring devices. These vaginal myographs suffer from a wide range of inherent problems. They are extremely expensive and most of the devices can be operated only by skilled health professionals after extensive specialized training.
There is no guarantee that these vaginal myographs measure the strength of contraction by the vaginal musculature. The level of electrical activity measured by these devices is determined by several variables, including the number of motor units firing, the rate of firing, the proximity of the motor units to the electrode, and the chemical characteristics of the vaginal fluid that forms the interface between the electrodes and the vaginal walls. These variables can give misleading variations in readings from one person to the next. The response of a vaginal myograph can also be affected by the contractions of muscles proximate to but distinct from those surrounding the vagina, such as the adductors or other hip muscles. Because the electrical signals picked up by the probe are at the microvolt level, vaginal myographs are extremely sensitive to electromagnetic interference. In addition, great measurement errors may occur when the pelvic floor tissue, or vaginal tissue, moves relative to the inserted myograph. Due to these movements an artificial increase in myographic activity arises with no relation to increased electrical activity of the examined tissue.
DE-A1-197 53 030 describes a probe to be inserted into a person's vagina or rectum and having a sensor for dynamically ascertaining the force applied by contraction of the pelvic floor muscles. The probe can be used by a physician in order to get information on the force that can be mobilised by contraction of the pelvic floor muscles by guidance of which a suitable treatment of the incontinence will be decided; surgery should not be resorted to if there is a possibility to improve the muscle strength e.g. by muscle exercise. The probe can also be used by the person at home in order to check the progress of improvement achieved by muscle exercise.
The therapeutic effect of vibratory stimulation on the human body has been well documented. Vibration at low frequencies applied to tissue increases blood circulation due to the increase in capillary dilation. The increased blood flow increases the consumption of oxygen and nutrients by muscles and improves the regeneration process. The result is an improved muscular tone, elasticity and contractile capacity.
U.S. Pat. No. 5,782,745 issued Jul. 21, 1998 to T. V. Benderev describes a device and method for assessment and treatment of urinary and fecal incontinence wherein a probe to be inserted into the vagina or the rectum is provided with a vibrator to provide vibratory stimulation to the vaginal or anal wall and/or adjacent muscles to facilitate strengthening of the pelvic floor muscles. The vibrator may be operated on a timed cycle.